Number of parallel moc or uic processes to start when using AUTOMOC and AUTOUIC.
The custom <origin>_autogen target starts a number of threads of which each one parses a source file and on demand starts a moc or uic process. AUTOGEN_PARALLEL controls how many parallel threads (and therefore moc or uic processes) are started.
By default AUTOGEN_PARALLEL is initialized from CMAKE_AUTOGEN_PARALLEL.
See the cmake-qt(7) manual for more information on using CMake with Qt.